energy and enzymes part 1

Question 1

Free energy

Answer 1

Usable energy that can do work
Change in free energy calculated by:
deltaG= Gproducts-Greactants
When a polypeptide(any macromolecule) is broken down into its smaller monomers via hydrolysis, energy is released

Question 2

What type of reaction is eating

Answer 2

Catabolic reaction

Question 3

Catabolic reaction

Answer 3

Reaction that breaks down large molecules into smaller units
Hydrolysis reaction to break polymers down into monomers
Energy(that was stored in the bonds holding the monomers together) is released
Exergonic

Question 4

Exergonic reactions

Answer 4

Reactions where energy is released
Products have lower energy than reactants
Spontaneous = delta G is <0

Question 5

What type of reaction is the incorporation of amino acids

Answer 5

Anabolic reaction
Amino acids are absorbed through the intestine after you eat and digest food, and released into the blood
They are then taken up by cells and used to build new proteins

Question 6

Anabolic reaction

Answer 6

Building larger molecules from smaller units

Question 7

Endergonic reaction

Answer 7

A reaction that requires energy input
Products have higher energy than reactants
Delta G is positive

Question 8

What is the energy currency of cells?

Answer 8

The nucleotide, ATP
Adenosine triphosphate

Question 9

Why does atp have energy

Answer 9

There are three phosphates in an ATP molecule and phosphate groups are negatively charged
The negative charge between the phosphate groups that are held close together, is the reason that ATP has a lot of potential energy

Question 10

How does ATP act as energy currency7

Answer 10

Energy trapped in gradients(H+) or covalent bonds can be captured by the synthesis of ATP from ADP
In cellular respiration the H+ gradient results in phosphorylation of ATP from ADP but ATP is used in many steps of cellular respiration to allow for phosphorylation of other substances

Question 11

Features of ATP

Answer 11

3 negative charges from triphosphate group results in an enormous source of potential energy due to the groups repelling one another
ATP stores energy in the phosphate group covalent bonds
Hydrolysis of ATP releases energy to drive endergonic reactions
ATP is the building block for nucleotides
ATP phosphorylates targets
ATP is rechargeable
ADP can be phosphorylated to turn into ATP

Question 12

Coupled reactions

Answer 12

Reactions where you use exergonic energy to drive endergonic processes

Question 13

How can ATP help with transport of substances?

Answer 13

ATP can phosphorylate proteins to change their conformation and allow things to be transported
Ex: if ATP phosphorylates a transport protein in the phospholipid bilayer, it can cause it to go through a conformational change and transport solutes across the membrane

Question 14

How do enzymes speed up reactions?

Answer 14

Reduce the activation energy required to start a reaction
Promote substrates into a transition state

Question 15

Enzymes

Answer 15

Important to all organisms
Catalyze important cellular reactions
Found in small amounts
Not consumed during the reaction

Question 16

Enzyme substrate complex

Answer 16

Substrates enter active sites of the complex and held there by weak interactions
The active site lowers the activation energy of the reaction
Substrates are converted to products
Products are released and active site is available for new substrates

Question 17

How does pH affect proteins

Answer 17

Changes in pH can denature proteins and cause them to lose/change their function

Question 18

overall equation of cellular respiration

Answer 18

C6H12O6 + 6o2 → 6co2 + +6H2O+energy(atp)

Question 19

point of cellular respiration

Answer 19

• to metabolize carbohydrates to get energy
  -enzymes catalyze the breakdown of macromolecules(glucose) into stored energy
• we need this energy to fuel cellular functions

Question 20

four stages of energy harvest

Answer 20

1.glycolysis
2.pyruvate oxidation
3.citric acid cycle
4.oxidative phosphorylation

Question 21

redox reactions in cellular respiration

Answer 21

NADH and FADH2 are electron carriers that link all the stages of cellular respiration
they are oxidized and reduced in order to carry electrons in the process

Question 22

why are there so many steps in cellular respiration

Answer 22

We dont want to explosively release all of the energy from glucose, we want to get a little bit of atp at a time

Question 23

Glycolysis (phases and where it occurs)

Answer 23

occurs in two phases:
1.Energy investment stage
2.Energy harvesting stage
Occurs in cytoplasm

Question 24

goal of glycolysis

Answer 24

oxidize glucose in ten steps
- produce pyruvate (2 3 carbon chains from 1 6 carbon chain)

Question 25

glycolysis net reaction

Answer 25

glucose + NAD+ + 2ADP + 2Pi
–>
2 pyruvate + 2 NADH + 2H+ + 2ATP + 2H2O

Question 26

ATP usage and gross from two phases of glycolysis

Answer 26

energy investment phase = use 2 ATP

energy harvesting phase = make 4 ATP + 2NADH

net gain of 2ATP

Question 27

Substrate phosphorylation

Answer 27

Making ATP from ADP + Pi
Enzyme combines ADP + Pi
ATP has more potential energy than ADP + Pi

Question 28

Structural features of mitochondria

Answer 28

2 membranes
Outer membrane
Inner membrane

Intermembrane space
In between the outer and inner membrane

Question 29

Pyruvate oxidation

Answer 29

After glycolysis, a transport protein shuttles pyruvate into the mitochondrial matrix

Pyruvate is oxidized by coenzyme A to turn into acetyl CoA

In the process, CO2 is released and NAD+ is reduced into NADH

Occurs in mitochondrial matrix

Acetyl needs coA to get through intermembrane of mitochondria
Then the coA release from acetyl

makes 1nadh per pyruvate

Question 30

Citric acid cycle

Answer 30

Aerobic cycle
Occurs in interspace of mitochondria/ matrix
Enzymes catalyze the reactions
Citric acid is oxidized in the cycle (CO2 released)
2 CO2 is released per cycle
6 nadh, 2 atp, 2 fadh2, 4 co2 per one glucose

Question 31

Every nadh and fadh produces how many atp

Answer 31

Every nadh produces three atp
Every fadhs produces 2 atp

Question 32

Oxidative phosphorylation

Answer 32

etc and chemiosmosis

Proteins of electron transport chain pump protons out of the matrix of the mitochondria into the intermembrane space
Create an electrochemical gradient

NADH and FADH2 carry electrons to electron transport chain and donate them

Proteins use the electrons that are donated to power their pumping of protons across the electrochemical gradient

They pass the electron from one protein to the next until it reaches the last electron acceptor, oxygen
Forms h2o

Chemiosmosis
Use concentration of protons to power ATP synthase
Adp and pi are put in motor which turns when proton goes through it, producing ATP
Oxidative phosphorylation

Question 33

Fermentation

Answer 33

Nadh and fadh2 can’t donate electrons to the transport chain
Glycolysis can keep going
produces a small amount of ATP when oxygen isn’t available

Question 34

fermentation in humans

Answer 34

instead of nadh being sent to etc from glycolysis, the nadh donates its electrons to pyruvate to form lactate then lactate uses its electrons to reduce NAD+ and the cycle continues

oxidizing NADH produces little bit of ATP

alcohol fermentation produces ethanol instead of lactate

Question 35

Feedback inhibition of cellular respiration

how is cellular respiration monitored

Answer 35

When we dont have enough energy, we produce AMP which stimulates a protein that promotes glycolysis and cellular respiration

When we have enough atp this signals to inhibit the use of that same protein, stopping glycolysis and cellular respiration from occurring
Products inhibit or stimulate